What to Know About Testosterone Injections

injection needle

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When people think of hormone imbalances and hormone therapy, they usually think of women, who experience many significant hormonal changes as they move through (and beyond) their reproductive years. But males can experience hormonal imbalances and deficiencies as well, which can affect their growth, development, reproductive systems, and physical and mental health.

Sometimes men and boys—or people born with male anatomy—are prescribed testosterone injections to remedy these issues. However, most experts caution that the testosterone injections—while helpful at times—should only be used in certain circumstances, and under the careful eye of a doctor.

What Is Testosterone?

Testosterone is the dominant male sexual hormone. Testosterone starts being produced in greater quantities when boys hit puberty and is responsible for the maturity of male secondary sexual characteristics. Testosterone continues to be produced throughout a male’s lifetime and helps sustain muscle mass, bone mass, sex drive, sperm production, and red blood cell production.

The normal range of testosterone levels in grown males is about 300 ng/dL to 1000 ng/dL. Testosterone levels tend to fluctuate throughout the day, with the highest levels in the early part of the day, and lowest levels in the latter part of the day. It’s normal for testosterone levels to change throughout a male’s lifetime and decline as they age.

What Are the Signs of Low Testosterone?

The signs of low testosterone vary according to age.

In adolescents, low testosterone may look like:

  • Delayed signs of puberty, including testes that don’t show signs of maturity, no penis widening or lengthening, and lack of pubic or facial hair
  • No signs of puberty by age 14

In adult makes, signs of low testosterone may include:

  • Decreased sex drive
  • Low sperm count
  • Erectile dysfunction
  • Fatigue
  • Depression
  • Osteoporosis
  • Decreased muscle mass

It’s normal for testosterone levels to decrease as you get older. Signs that your testosterone levels may be causing an issue for you include:

  • Low sex drive
  • Erectile dysfunction or impotence
  • Extreme exhaustion
  • Inability to concentrate
  • Low mood
  • Osteoporosis
  • Low muscle mass

How to Find Out If You Have Low Testosterone

If you or your child is showing signs of low testosterone, you should visit a doctor. Low testosterone isn’t something that can be self-diagnosed or diagnosed based on symptoms alone. Patients must have their blood drawn and hormone levels accessed. Since testosterone levels are generally highest in the morning, this might mean a morning blood draw.

Doctors will likely measure a patient’s total testosterone level. If total testosterone levels are normal, but there are still signs of low testosterone, other blood tests might need to be performed, including free testosterone levels and SHBG (sexual hormone-binding globulin) levels. Your doctor will determine which type of blood test is best for you and your particular situation.

How to Know If Testosterone Injections Are Right for You

Testosterone injections (synthetic testosterone injected into patients in an effort to increase testosterone levels) are a helpful way to raise testosterone levels in someone who is deficient. At the same time, they are not for everyone and many experts recommend using caution and not overprescribing testosterone injection therapy.

In general, testosterone injections are used in a few specific scenarios:

  • Delayed puberty
  • Erectile dysfunction/impotence
  • Hormonal imbalances causing medical problems

It’s equally important to understand what testosterone injection should not be used for. For example, experts do not generally recommend that testosterone injections be used to:

  • Increase athletic performance
  • Enhance mood
  • Decrease fatigue
  • Decrease the natural effects of aging

What Are the Health Risks of Testosterone Injections?

Any male with a history of cancer (prostate or breast) should not use testosterone injections. Testosterone injections can increase your risk of heart attack, especially if you are older, so people with cardiac conditions should avoid testosterone injections. The same is true of someone who has liver or kidney disease as well as anyone allergic to sesame or castor oil.

Testosterone Injections and Male Fertility

It may seem logical that testosterone injections would raise sperm counts in a male who is struggling with fertility issues. However, using testosterone injections for this purpose is usually not recommended, as testosterone injections can actually decrease sperm counts.

If you are interested in possibly using testosterone injections to remedy a sperm count issue, you should speak to a reproductive endocrinologist for more information.

What Are Testosterone Injection Side Effects?

Rarely, testosterone injections can cause allergic reactions. Signs of an allergic reaction to a testosterone injection include:

  • Hives
  • Swelling of the face, lips, tongue, mouth, and throat
  • Struggling to breathe
  • Shortness of breath
  • Coughing

In addition, other adverse reactions to watch out for include:

  • Chest pain
  • Chest pain/pressure that spreads to your jaw and shoulder
  • Difficulty breathing
  • Seizures
  • Sudden mood changes
  • Edema (swelling) of feet and ankles
  • Erectile dysfunction
  • Painful urination
  • Signs of blood clots (redness in arms/legs, swelling, rapid breathing, chest pain)
  • Signs of a stroke (headache coupled with slurred speech and balance issues)

If you have any of these symptoms, call your doctor right away or head to the nearest emergency room.

Alternatives to Testosterone Injections

Because of some of the side effects of testosterone injections and the instances where they are prohibited, some males are looking for alternatives to testosterone injections, especially if their symptoms are milder, such as low mood, fatigue, or decreased sexual libido.

For people with milder symptoms of low testosterone, lifestyle chances might be enough for a needed boost. These are some things to try before getting on board with testosterone injections:

  • Symptoms of exhaustion and decreased sex drive can be corrected with regular exercise, a balanced diet, and improved sleep hygiene.
  • Seeking counseling for sexual issues may help, as sexual performance and drive can be a mind/body issue.
  • Make sure to get a full health workup. Issues like erectile dysfunction may be caused by other medical issues than low testosterone, especially as you get older.

A Word from Verywell

Testosterone injections can be very helpful for certain individuals in specific situations. At the same time, testosterone injections may be overprescribed or prescribed when other, safer measures can be implemented.

It’s important to understand the risk of using testosterone injections, and balance that with your own (or your child’s) needs. As always, all medical decisions regarding testosterone injections should be made under the guidance of your medical team.

3 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Carnegie C. Diagnosis of hypogonadism: clinical assessments and laboratory tests. Rev Urol. 2004;6 Suppl 6(Suppl 6):S3-S8.

  2. University of Michigan Health. Testosterone Injection.

  3. Penn Medicine. The Truth About Testosterone and Male Fertility.

Additional Reading

By Wendy Wisner
Wendy Wisner is a lactation consultant and writer covering maternal/child health, parenting, general health and wellness, and mental health. She has worked with breastfeeding parents for over a decade, and is a mom to two boys.